| Message ID | 20220827153815.124475-1-duoming@zju.edu.cn (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | c0955bf957be4bead01fae1d791476260da7325d |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] ethernet: rocker: fix sleep in atomic context bug in neigh_timer_handler | expand |
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Sat, 27 Aug 2022 23:38:15 +0800 you wrote: > The function neigh_timer_handler() is a timer handler that runs in an > atomic context. When used by rocker, neigh_timer_handler() calls > "kzalloc(.., GFP_KERNEL)" that may sleep. As a result, the sleep in > atomic context bug will happen. One of the processes is shown below: > > ofdpa_fib4_add() > ... > neigh_add_timer() > > [...] Here is the summary with links: - [net] ethernet: rocker: fix sleep in atomic context bug in neigh_timer_handler https://git.kernel.org/netdev/net/c/c0955bf957be You are awesome, thank you!
diff --git a/drivers/net/ethernet/rocker/rocker_ofdpa.c b/drivers/net/ethernet/rocker/rocker_ofdpa.c index bc70c6abd6a..58cf7cc54f4 100644 --- a/drivers/net/ethernet/rocker/rocker_ofdpa.c +++ b/drivers/net/ethernet/rocker/rocker_ofdpa.c @@ -1273,7 +1273,7 @@ static int ofdpa_port_ipv4_neigh(struct ofdpa_port *ofdpa_port, bool removing; int err = 0; - entry = kzalloc(sizeof(*entry), GFP_KERNEL); + entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) return -ENOMEM;
The function neigh_timer_handler() is a timer handler that runs in an atomic context. When used by rocker, neigh_timer_handler() calls "kzalloc(.., GFP_KERNEL)" that may sleep. As a result, the sleep in atomic context bug will happen. One of the processes is shown below: ofdpa_fib4_add() ... neigh_add_timer() (wait a timer) neigh_timer_handler() neigh_release() neigh_destroy() rocker_port_neigh_destroy() rocker_world_port_neigh_destroy() ofdpa_port_neigh_destroy() ofdpa_port_ipv4_neigh() kzalloc(sizeof(.., GFP_KERNEL) //may sleep This patch changes the gfp_t parameter of kzalloc() from GFP_KERNEL to GFP_ATOMIC in order to mitigate the bug. Fixes: 00fc0c51e35b ("rocker: Change world_ops API and implementation to be switchdev independant") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> --- drivers/net/ethernet/rocker/rocker_ofdpa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)